police say they died when 20-year-old adam lanza forced his way into sandy hook elementary friday morning and started firing. president obama will travel to newtown later today to attend a memorial service. he'll also visit with the victims' families, this as investigators try to figure out why they were killed. people who knew lanza describe him as odd and remote. police say he shot and killed his mother nancy lanza at home and then drove to the elementary school he attended as a boy. authorities say the guns he used belonged to his mother. >> she had a gun collection and she was a real gun enthusiast and she would go target practice shooting with her kids. >> reporter: 26 children and adults were killed during the shooting, including teacher vicki soto. at a vigil for her last night, soto's sister asked everyone to hug the people they love. [ indiscernible ] >> reporter: family members say soto died shielding her students from the gunman. and since he took office, the president has traveled three times to comfort victims after a mass shooting. today's visit will be the fourth. in newtow